Improvements

[gokulkrishh]

• [x] Change user connecting logic
• [x] Tab closing is not working in mobile
• [x] Offline support in firebase API
• [x] Fixes for responsiveness in desktop and table
• [x] Intro screen for the first time visit to app
• [ ] Fix for SW Precache config for google fonts
• [ ] Add doodle background
• [ ] Lighthouse score improvements
• [ ] Option to enable push notification